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| author | Alexander Shishkin <alexander.shishkin@linux.intel.com> | 2019-08-21 15:47:24 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2019-08-26 12:00:13 +0200 |
| commit | 539f7c26b41d4ed7d88dd9756de3966ae7ca07b4 (patch) | |
| tree | 6595ea87f5ddda34da06f0e5a2b7cde445248c22 /arch/x86/events | |
| parent | fffec50f541ace292383c0cbe9a2a97d16d201c6 (diff) | |
| download | linux-539f7c26b41d4ed7d88dd9756de3966ae7ca07b4.tar.gz | |
perf/x86/intel/pt: Use pointer arithmetics instead in ToPA entry calculation
Currently, pt_buffer_reset_offsets() calculates the current ToPA entry by casting pointers to addresses and performing ungainly subtractions and divisions instead of a simpler pointer arithmetic, which would be perfectly applicable in that case. Fix that. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/20190821124727.73310-4-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/events')
| -rw-r--r-- | arch/x86/events/intel/pt.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c index f269875fb85f..188d45f52b64 100644 --- a/arch/x86/events/intel/pt.c +++ b/arch/x86/events/intel/pt.c @@ -1030,8 +1030,7 @@ static void pt_buffer_reset_offsets(struct pt_buffer *buf, unsigned long head) pg = pt_topa_next_entry(buf, pg); buf->cur = (struct topa *)((unsigned long)buf->topa_index[pg] & PAGE_MASK); - buf->cur_idx = ((unsigned long)buf->topa_index[pg] - - (unsigned long)buf->cur) / sizeof(struct topa_entry); + buf->cur_idx = buf->topa_index[pg] - TOPA_ENTRY(buf->cur, 0); buf->output_off = head & (pt_buffer_region_size(buf) - 1); local64_set(&buf->head, head); |